Flux transfer event

A flux transfer event (FTE) occurs when a magnetic portal opens in the Earth's magnetosphere through which high-energy particles flow from the Sun. This connection, while previously thought to be permanent, has been found to be brief and very dynamic. The European Space Agency's four Cluster spacecraft and NASA's five THEMIS probes have flown through and surrounded these FTEs, measuring their dimensions and identifying the particles that are transferred between the magnetic fields.^{[citation needed]}